Paolo Longo, Ph.D., Gatan, Inc.
Sample courtesy of University of Glasgow
Microscope courtesy of Dr. Yan Xin at Florida State University, Tallahassee, FL
Acknowledgement to Dr. Toshiro Aoki at Jeol USA (now at ASU) for helping set up microscope for experiment.

Dumbbell structure of GaAs on left hand side of color map is clearly resolved, and Ga and As atomic columns are visible. Interface region shows presence of Ga2O monolayer responsible for keeping Fermi level unpinned, which allows the electronic device to be turned on or off.